Gemini: We can rebuild it, we have the technology

[rancamp]

Not arguing the point, but....<br /><br />mrmorris:<br /> />A rucksack such as a paratrooper would have might<br /> />be on the order of 60-80 pounds. With the weight of<br /> />the paratrooper being on the order of 180 pounds -<br /><br />My bad, I should have thought this through. FYI, the paratroopers routinely jumped with full kit-bags, NOT rucksacks. In other words it weighed upwards of the same, to +1/2 (180-220lbs) of gear. So I was DEFINATLY off with that one.<br />Sorry <img src="/images/icons/blush.gif" />)<br /><br />Randy

 

[yree]

HS reader Fedor Novozhilov pointed me to this Russian article that describes the development of a new rocket system called the "Ladoga-1P" (Ladoga is a lake near St. Petersburg). According to the Altavista translator, the system is a response to the SpaceX Falcon program. It will include both a two stage and a three stage model and will be powered with LOX/Kerosene engines. The two stage version will put 600-700 kg into LEO. The three stage version will put 150-200 kg into GEO or a Gemini type of capsule into LEO with two tourists for around 5M USD per tourist.<br />http://www.hobbyspace.com/Links/RLVNews.html

 

[mrmorris]

<font color="yellow">"...a new rocket system called the "Ladoga-1P" ..."</font><br /><br />Interesting. Be nice to have a backup to the Falcon-V... except that we're looking to win the ASP and that requires a US launcher...

 

[mrmorris]

I spoke earlier about picking a new name for G-X3 -- seeing as it's no longer really Gemini (nor is it really Apollo). I mentioned the possibility of using Gyrfalcon -- to provide continuation of the G-X3 designation as well as tie-in to the SpaceX bird of prey motif (Falcon/Kestrel/Merlin). However, this afternoon I came up with the perfect name, so I figured I'd post the sucker. Henceforth, the 'G' in G-X3 stands for 'Gryphon'.<br /><br />This seems to be perfect to me. It keeps with the bird-of-prey motif (sort of). Also, the Gryphon is a mix between an eagle and a lion (hopefully I don't have to draw anyone a picture on why that's appropriate). My cynical side says that the mythological nature of the Gryphon matches well with the existance of G-X3. Finally, one can call it a half-nod to our NASA admin as well -- although it's a bit early to be erecting monuments to him just <b>yet</b>.<br /><br />At any rate, <b>I</b> think the name fits. <img src="/images/icons/smile.gif" />

 

[mrmorris]

<font color="yellow">"I emailed the British Interplanetary Society..."</font><br /><br />Finally received a response from my email to the BIS. They have a single copy remaining of that issue that they'll sell for 10 pounds. Frankly, I'm not *quite* that interested -- esp as I don't know if the article has much (or any) more info than what's in Astronautix.<br /><br />If anyone is interested, Mary McGivern has indicated that she's set the copy aside awaiting my reply. I'll let her know that I renounce all claims to the issue, but have notified a bevy of other space geeks and that there may be another person more interested. The email address is: mail@bis-spaceflight.com

 

[nacnud]

Interesting, we don't want the entire thing, especialy if its the last one, but do you recon they'd photocopy the relavent section?

 

[mrmorris]

<font color="yellow">"do you recon they'd photocopy the relavent section?"</font><br /><br />I specifically mentioned that I was interested in a photocopy of the one article. No mention of this was made in the reply, which I take for a 'No'.

 

[gunsandrockets]

I've read the 30 pages of the BIS story on the MRC. Report later today.

 

[mrmorris]

<font color="yellow">"I've read the 30 pages..."</font><br /><br />30 pages actually makes it more interesting (i.e. for buying the journal). Will be interested to see your report. Alternately.... you don't happen to have a means of scanning the suckers and making them available on a website somewhere, do you...? <img src="/images/icons/smile.gif" />

 

[nacnud]

Or how about an email to someone that can host it? Anyone volunteer?

 

[gunsandrockets]

The library had back issues of the Journal of the British Interplanetary Society on microfilm. The four articles on the MRC are on Vol. 42, pages 67-96, 1989. Here is some of the information I read about the BAE Multi-Role Capsule.<br /><br />Surprises<br /><br />The encyclopedia astronautica report on the MRC... <br /><br />http://www.astronautix.com/craft/mulpsule.htm<br /><br />has problems. The capsule is called the Multi-Role Capsule, not the Multi-Role Recovery Capsule. The MRC is expendable, not reusable. The MRC has a simple cone shape, not the Gemini like shape suggested by the astronautix artwork. Another surprise is the reaction control system doubles as retro-rockets and are located in nose-mounted "thruster pods."<br /><br />Basics<br /><br />The MRC was designed for eight roles in the 1990's:<br />1)independent European manned access<br />2)manned spaceflight technology development<br />3)unmanned microgravity laboratory<br />4)US Space Station escape system<br />5)US Space Station contingency access<br />6)MTFF (man tended free flyer) and Polar Platform servicing<br />7)European Space Station crew access<br />8)European Space Station escape system<br /><br />As can be seen by this list, at least in 1989 the Europeans had some ambitious goals for the 1990's!<br /><br />It was expected that 16 capsules would be built and flown over the 15 year lifespan of the program. Because the estimated flight rate would be so low, "the benefits of a reusable system are not obvious", though some equipment was expected to be salvaged and possibly reused.<br /><br />Performance<br /><br />The in orbit mass was required to be no more than 7 tonnes to match the payload limits of the Ariane 4 launch vehicle. The crew would normally be four plus 500 kg of cargo. For emergency escape missions two extra seats replace the cargo bay. For unmanned missions a payload of 1500 kg could be carried.<br /><br /><br />Active life s

 

[mrmorris]

<font color="yellow">"...we were bouncing ideas around for slowing down the vehicle landing speed."</font><br /><br />The rucksack conversation got me thinking about the impact speed on landing. While I'm advocating using the Apollo CM shape, and the Apollo CM chutes, the capsule mass should actually be considerably <b>less</b> than the original Apollo CM. It has to be -- if the Falcon V is going to get it into orbit. I got to wondering exactly what the difference in terminal velocity would be given the G-X3's lower mass with Apollo chutes.<br /><br />The MODAP document gives good stats for the this. It was to mass 11,022 kg, and the three chutes alone would have reduced terminal velocity to ~24 ft/s. The retro-rockets were then to have fired eight second before landing to reduce the impact velocity to 9 ft/s.<br /><br />Terminal velocity for a parachute descent can be calculated by:<br /><br />D = sqrt( (8 m g ) / (pi p Cd v2))<br /><br />D - diameter of chute (round)<br />m - mass of system<br />g - acceleration due to gravity<br />p - air pressure<br />Cd - coefficient of drag (varies by chute, we'll use the figure I found of 1.5)<br />v - terminal velocity<br /><br />The Apollo/MODAP used three 27 meter chutes. Since my fomula is for a single round chute, we'll say each chute slowed 1/3 of the mass of the capsule, or 3674 kg, and we'll use 1.22 kg/m3 as the atmospheric density. Finally, the terminal velocity NASA calculated for the MODAP was ~24 fps (7.6 m/s). Plugging those in to the equation, we get:<br /><br />D = sqrt( (8 m g ) / (pi p Cd v2))<br />27 m = sqrt ( ( 8 * 3674 kg * 9.8 m/s2 ) / (3.1416 * 1.22 kg/m3 * 1.5 * 58 m2/s2) )<br />27 m = sqrt ( ( 295097.6 kg m/s2 ) / ( 333 kg / m s2 ) )<br />27 m = sqrt ( 886 m2)<br />27 m ~ 29.7 m<br /><br />Close enough to tell me they were using approximately the same figures. They probably used a slightly different value for Cd. If they used 1.8 for Cd, the figures would have matched. Likewise -- they may have picked a

 

[mrmorris]

This was originally planned to be a the start of a new thread -- seeing as this one is getting a bit too long to easily read. Also, much of it -- while not strictly speaking off-topic, is definitely straying from the central point a bit. However, seeing as the updates have slowed a great deal, I decided to put it in here as the 'reference post' that Arobie requested... a long long <b>long</b> time ago.<br /><br />The premise for this thread is to explore -- in as much detail as feasible -- the potential design choices for a spacecraft capable of winning the Americas Space Prize. To do that -- there are several design goals that have been set for the craft (all of the ASP rules obviously apply -- the following is an abbreviated list of the ones which significantly influence the design)):<br /><br />-- It must be light enough that it can be launched from the proposed SpaceX Falcon-V booster to an ISS-compatible orbit (~5400 kg to 400km), or to a lower orbit and have the internal propulsion capability to increase the orbit to 400km.<br />-- It must carry five people.<br />-- 80% of the combined mass of the spacecraft plus booster must be reusable.<br />-- The spacecraft must complete two missions within 60 days to claim the ASP. (It's been noted that this need not be the <b>nominal</b> turnaround period).<br />-- The spacecraft must be capable of docking with Bigelow's space station and remain on station for at least six months.<br /><br />In designing the vehicle -- the intent is *not* to create a general purpose spacecraft for operations in LEO, but to optimize the design for ferrying people from ground to a space-station and back again. To keep it within the mass and reuse constraints, the design is restricted to a capsule, with no orbital module (ala Soyuz/Shenzhou), <b>very</b> volume-restricted crew quarters, and a minimal ECLSS. To make the restricted space and ECLSS practical -- the transit time must be minimized. Soyuz takes ~2-3 days from launch to docking, and

 

[grooble]

bump. Falcon IX.

 

[arobie]

<font color="yellow">I decided to put it in here as the 'reference post' that Arobie requested... a long long long time ago.</font><br /><br />Thank You. <img src="/images/icons/smile.gif" /><br /><br />Very, very Impressive. Excellent work!

 

[tempel1]

Dear friends <br />Go here please:<br />http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=117 <br />” The spacecraft's VELOCITY RELATIVE TO THE SUN is at about 26 kilometers per second (about 59,250 miles per hour). Cassini is now more than 9 million kilometers (almost 6 million miles) from Earth”. <br /><br />Since our probe is launched from the earth, it has already a velocity of 65,000 miles per hour (earth's velocity). <br /><br />Why have NASA engineers steered Cassini on this trajectory? <br /> http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=h_cassini_trajectory_02.gif&cap=The <br /><br />Instead of increasing Cassini's velocity they have slowed down it at 59,250 miles per hour. <br /><br />NASA engineers think the earth is the center of our solar system and don't consider earth's velocity. <br /><br />In this wrong way Cassini has travelled for 2 200 000 000 miles to meet Saturn. <br /><br />Cassini would have been able to fly along a straight line travelling for less than 1 000 000 000 miles. <br /><br />65,000 miles per hour (earth velocity) + 36,000 miles per hour (spacecraft's velocity) = 101,000 miles per hour <br /><br />1 000 000 000 miles : 365 days : 24 hours : 101,000 miles per hour = 1.13 years <br /><br />If NASA engineers considered the earth's velocity, Cassini could meet Saturn in one year! <br />

 

[mrmorris]

<font color="yellow">"Falcon IX. "</font><br /><br />The Falcon IX isn't really a reason to redesign G-X3. Everything else aside, the increased price tag would put it outside the range of the primary reason for G-X3 -- namely the ASP.<br /><br />However, let's speculate on the possibilities for the increased lift ability of the Falcon IX in relation to the G-X3. We don't really need more people -- there's no reason to take more than five... maybe six to orbit. The spacecraft as designed already has all of the functional elements needed for an LEO taxi. However, we could build 'Big GX-3', which uses the basic electronics & functional elements of G-X, but adds a 'Big-Gemini' style section to the rear which introduces possibilities like:<br /><br />Micro-G lab -- Reduce crew to 1-2 people, dedicate the add-on section to experimentation (with additional ECLSS and power). This would provide for short duration Micro-G work (2-3 weeks) such as the shuttle provided -- at a much more reasonable cost. While the Bigelow CSS will have room for long-term experiements -- this would likely be something with a much lower cost<br /><br />Cargo capability -- In addition to crew rotation, the capsule can be used for logistics flight to resupply the station, or to bring up replacement/repair hardware for the CSS. It would also provide a much needed 'down' cargo capacity that the basic G-X3 can not.<br /><br />Or possibly no Big-G section, but rather something like:<br /><br />Lunar missions -- Going <b>way</b> out on a limb here, and have done <font color="red">zero</font>calculations to see if it's feasible. One of the things I hope to see in the VSE is a minimal space station in low-lunar orbit (i.e. like a single Bigelow module) that has a re-usable lunar lander for ferrying crew to/from the surface. So we create a service module for G-X3 (possibly/probably reduced to a four-person crew) that will act in the same capacity as the Apollo SM. With G-X3 weighing o

 

[nacnud]

EML-1 might be a better place for the Luna station, and would require less delta v

 

[mrmorris]

<font color="yellow">"...and would require less delta v"</font><br /><br />I don't really want to take the thread on a lunar tangent. However -- while EML-1 would require less dv from Earth, it would mean that the lunar lander would require more. Dunno how much by any means, or what the optimization is, or pretty much anything. As I said -- haven't really spent any time working figures. However, my WAG would be that it would be more useful to have the lunar surface- />station dv minimized than the earth surface->station dv... at least from NASA's perspective. That particular optimization may well trash the GX-3 lunar taxi, of course. <img src="/images/icons/smile.gif" />

 

[rubicondsrv]

Can't let this thread dissapear off the top 20 <div class="Discussion_UserSignature"> </div>

 

[mrmorris]

I don't post to this thread just for the heck of it. I won't lose track of it. However, I just did some calcs based on an interesting factoid I ran across this afternoon:<br /><br /><i>"The 12-foot-high Apollo spacecraft command module contains about fifteen miles of wire, enough to wire 50 two-bedroom homes. "</i><br /><br />None of my figures have tried to account for the mass of the wiring in the craft. Using modern electronics, this will be <b>massively</b> reduced. I don't know what guage the wiring of the command module was, but you can figure it likely averaged around 16 or 18 guage. Working mass figures for copper wire in that range:<br /><br /><b>16 guage wire:</b><br />x = 0.3222554 pound/cubic inch * 3.14 * 0.025 in ^2 * 950,400 inch<br />x = 601 pounds<br /><br /><b>18 guage wire:</b><br />x = 0.3222554 pound/cubic inch * 3.14 * 0.02 in ^2 * 950,400 inch<br />x = 384 pounds<br /><br />A modern CM then should be able to shave off several hundred pounds in wiring alone. Nice. <img src="/images/icons/smile.gif" /><br /><br />*edit* -- Just thought -- much of the wire length might be very low-voltage. Might tip the average closer to 20-guage. Calculating for this, we get:<br /><br /><b>20 guage wire:</b><br />x = 0.3222554 pound/cubic inch * 3.14 * 0.016 in ^2 * 950,400 inch<br />x = 246 pounds<br /><br />... still better than a kick in the head. But then most things are.

 

[mrmorris]

SpaceX just officially announced the Falcon 9. The big news from this is that they updated the site and provided this quote:<br /><br /><i>"However, in the case of Falcon 5 (and Falcon 9), both stages are designed for reuse, making them the world's first fully reusable launch vehicles."</i><br /><br />This makes it much easier for the G-X3 to make the 80% reusability requirement for the ASP. Projected price of $27 million for the Falcon 9 puts it outside the range of possibility for the ASP follow-on contract at $33 million/flight. Ergo we still need to have the G-X3 stay in a mass range that can be handled by the V.

 

[mrmorris]

I've been thinking about the implications of a reusable second-stage of the Falcon-V and its implications for G-X3. Pulling from an earlier post of mine on this thread, there are four basic options I see on when the second stage and G-X3 part company:<br /><br /><i>1. SS takes G-X3 to 200km, separates and either performs a short DO burn or simply allows the orbit to decay (I forget the timeframe of a 200km orbit... but it's not long). G-X3 then would need to have sufficient RCS/OMS capability to lift its orbit from ~200km to ~400km, approach the station, dock, undock, perform a DO burn, and use RCS for controlled re-entry. <br /><br />2. SS takes G-X3 to ~400km, separates and performs a DO burn to re-enter. G-X3 then would need to have sufficient RCS/OMS capability to approach the station, dock, undock, perform a DO burn, and use RCS for controlled re-entry. <br /><br />3. SS takes G-X3 to ~400km, approaches and docks with the station, then separates and performs a DO burn to re-enter. G-X3 then would need to have sufficient RCS/OMS capability to undock, perform a DO burn, and use RCS for controlled re-entry. <br /><br />4. SS takes G-X3 to ~400km, approaches and docks with the station, undock, perform a DO burn, then separate. G-X3 then would need only to have sufficient RCS for controlled re-entry. </i><br /><br />Given a re-usable second stage, I think that option four takes center stage. The second stage of the Falcon-V could act essentially as a service-module for G-X3.<br /><br />It's been noted in M&L that the specs of the Falcon-V have been changed. It used to be 30m tall -- and it has been upsized to 47m. Essentially it's become a Falcon IX with four less engines and lots of empty tankage. Unfortunately, this has reduced its payload and bumped its price. However, I can see some of this working in favor of G-X3. Namely:<br /><br />1. As mentioned earlier -- we have less throwaway mass so the 80% buffer just got larger.<br />2. Assuming the Second Stage of Falc

 

[mikejz]

Maybe for the LES you could have some sort of a dual mode system, where pairs of strap ons are attached to the payload adapter--and used either to asisst the 2nd stage during boost, or fired all together would just take the capsule away. Might be structual isssues however.

 

[mrmorris]

I decided to play around a bit with my 'LET-as-booster' concept. Searching the Web, I found a few specs on the Apollo Launch Escape Tower (quotes pulled out of context and from two different sites):<br /><br /><i>"The launch escape motor is 26 inches in diameter, 15 feet, 3 inches long and burns about 4,700 pounds of solid propellant to provide 155,000 pounds of thrust. <br />...<br />The first solid rocket motor is the Launch Escape Motor, which has four nozzles in the bottom part of the body. It carries the CM away from the booster during an emergency, providing about 147,000 pounds of thrust in 3.2 seconds of burning. <br />...<br />The second solid rocket motor is the Tower Jettison Motor, which has two nozzles in the center of the body. It is used to jettison the LES and BPC from the CM, either after a normal launch or after an emergency escape. It provides about 31,500 pounds of thrust in about one second of burning.<br />...<br />When there is no emergency, the LES is jettisoned with the BPC at 295,000 feet (89,900m), or about 30 seconds after second stage (S-II) ignition. (with the Saturn IB, 275,000 feet or about 20 seconds after second stage (S-IV) ignition.)"</i><br /><br />The first bit makes it clear how important it is that we find a non-emergency use for the LET. 4,700 pounds taken out of the 80% reusable mass fraction is *really* painful. Of course since G-X3 is lighter than the Apollo CM -- that much propellant wouldn't be required. The Apollo CM was ~5,800 kg. I've found ways to shave about 1,300 kg off of the CM so G-X3 would probably be more on the order of 4,500 kg or ~78% of the Apollo CM mass*. The LET solid propellant then would mass more on the order of 3,700 lbs to provide a comparable acceleration. 3,700 pounds is still a pretty big bite out of the reusability budget, though.<br /><br />OK -- so given the thrust available from the LET, we need to know the velocity at the time it's jettisoned. I found http://spider.ipac.</safety_wrapper